The International Health Regulations (IHR) provide a global framework for health security, requiring annual reporting on 35 indicators across 15 core capacities via the State Parties Annual Reporting (SPAR) tool. The COVID-19 pandemic exposed gaps in the IHR framework and monitoring systems, prompting calls for reform. This systematic review analyzed the correlations between IHR-SPAR scores and pandemic outcomes across nine studies (2020-2024), selected using the PRISMA guidelines. The study quality was assessed using the Joanna Briggs Institute's tool for cross-sectional studies. Of 1019 screened studies, nine met the inclusion criteria. Higher SPAR scores generally correlated with lower COVID-19 incidence and mortality, although some high-scoring countries experienced severe outbreaks. Middle-income countries showed the greatest improvement, particularly in risk communication and emergency response, while zoonotic disease capacities saw little progress. While the SPAR tool aids monitoring, it requires revisions to better reflect real-world pandemic responses. High SPAR scores do not always indicate effective crisis management. This study recommends integrating more dynamic, operational, and context-sensitive indicators to enhance the global preparedness for future health emergencies.